Assessment of prevalence of active pulmonary tuberculosis among patients with ocular tuberculosis

Background Tuberculosis (TB) is considered a multisystemic disease showing many extrapulmonary presentations. TB uveitis is one of the common forms of extrapulmonary TB. The lung is still the first organ to be attacked by TB, and pulmonary TB is the only infectious form of the disease. Aim The aim of the study was to detect the prevalence of active pulmonary TB among patients with TB uveitis. Patients and methods The present study included 37 patients with diagnosis of ocular TB on the basis of previous history, ocular examination, and exclusion of other suspected causes of uveitis. In addition, positive tuberculin skin test, or positive interferon-gamma release assays were carried out. All included patients were subjected to sputum examination for acid-fast bacilli and plain radiography of chest P-A view, and certain cases had a bronchoalveolar lavage. Patients with active pulmonary TB were detected. Both groups (patients with active pulmonary TB and patients with free chest) were compared with regard to all the previously mentioned studied parameters. Results The mean age of the studied patients was 34.8±12.5 years. All the studied patients showed positive tuberculin test with a mean of 18.5±3.4 mm. With regard to the Quantiferon Gold test, 34 patients (91.9%) had positive results. Concerning radiography, only 10 (27%) patients had normal radiograph, the rest of the patients showed various radiological lesions. Thirty (81.1%) patients were diagnosed to have active pulmonary TB. Sputum examination for acid-fast bacilli revealed that 22 (59.5%) patients had positive results; an additional eight patients (who had negative results on sputum examination) showed positive results when they underwent a bronchoalveolar lavage. There was no statistically significant difference with regard to all the previously mentioned parameters between patients with active pulmonary TB and patients with a free chest. Conclusion The present study revealed that a considerable percentage of the patients with TB uveitis had active pulmonary TB.